Safe Sparge Temperature

[cpsmusic]

Hi Folks,

Finally got a chance to have another go with my 10L Braumeister. The last batch I made with it came out noticeably astringent so this time I want to make sure that I don't make the same mistake. I'm pretty sure that the problem arose because my sparge water was too hot.

I realise that room temp is probably the safest sparge temp but if I want to try something higher what would be the safest temp that would avoid astringency but still give a reasonable extraction?

Cheers,

Chris

 

[Garfield]

Hey not sure about Braumeister but typical limit for sparge temperature is 77°c

 

[Jack of all biers]

Without you stating what your sparge temp was it's difficult to say conclusively, but more important than sparge water temp is sparge water pH. Sparge water temp can be 85C and pH below 5.6 and you won't get astringency extraction.
76-78C is the common recommended temp range, but that (from memory) it is more to do with the balance between sugar extraction efficiency (optimum liquefaction temp is 76C) and not extracting tannins and silicates from the grist. Getting the sparge water pH under 5.8 assists with making this less critical (think boiling the grist during a decoction, which incurs no extraction of tannins).

 

[Bonenose]

Have done the same when I started, from what I understand 75 degrees about right. You do want it to be hot to help extract the most out of your grain but I believe anything above 75 or so will start to extract tannins

 

[Bonenose]

Also as above check out water chemistry calculators and test your pH of sparge water if you can.

 

[MHB]

There isn't a hard right/wrong answer.
The hotter the better the extract recovery - the more tannin you will extract.
The higher the pH the more tannin you will extract.
If your sparge water is acidified to mash pH's (say 5.2-5.5pH) the practical upper limit is around 80oC (this is the industry standard). Some beep bed traditional UK systems (we are talking grain beds in the 1-2 meter deep range) used slightly hotter water as it cools before it gets to the bottom
Mark

 

[Ian176]

Hi Folks,

Finally got a chance to have another go with my 10L Braumeister. The last batch I made with it came out noticeably astringent so this time I want to make sure that I don't make the same mistake. I'm pretty sure that the problem arose because my sparge water was too hot.

I realise that room temp is probably the safest sparge temp but if I want to try something higher what would be the safest temp that would avoid astringency but still give a reasonable extraction?

Cheers,

Chris

I've only ever batch sparged and I have always done this at 75c, although I've only done 12 all grain batches. I'm no expert though

I seem to have good results this way, anyone have any thoughts on this

 

[HaveFun]

i use RO water to sparge, can i use Lactic Acid to adjust the pH ?

And how much Lactic Acid do i have to use to get the pH of the Sparge water down to pH 5.4 ?

Thanks
Cheers
Stefan

 

[cpsmusic]

Thanks for the replies. Think I'll go with 70 degrees just to be on the safe side. I'll look into ph testing for the next batch.

Brewing in progress!

Cheers!

 

[Jack of all biers]

i use RO water to sparge, can i use Lactic Acid to adjust the pH ?

And how much Lactic Acid do i have to use to get the pH of the Sparge water down to pH 5.4 ?

Thanks
Cheers
Stefan

Yes, Lactic can be used for this, without any issues. You probably need to ask yourself if you actually need to acidify your RO water though. RO water won't need much acid to get it down to pH 5.4, but it depends on the volume of sparge water you are using and concentrated percentage of Lactic acid you have. First question you need to answer is; What is the pH of your current end runnings? This may answer whether you actually need to add acid to your RO sparge water at all. If the end runnings aren't getting above 5.8, then don't bother with sparge acidification. If the end runnings never get above 6.0 and your sparge temp is 76-78C then the same applies. If you find astringency in your beers that has no other explanation, despite the end running pH and temps being in the right ranges, then give sparge acidificaiton to 5.4 a crack.*

I use Brewers Friend Advanced Water calculator, which has a tab for Sparge water Acidification to calculate this. I find that with my mains water the acid volume given by this calculator is always 1.3 times lower than is actually needed (this took me a few times to get this figure right, but it is consistent). That is with my particular mains water though, so I wouldn't say this would be across the board. The only way to know if the figure produced is correct is to test the actual pH.

So running 15L of RO sparge water through this calculator with 88% Lactic it throws out the figure of 0.01 ml acid needed to bring it to pH 5.4. As pointed out above, you should test the actual pH to see if it comes out at the pH you want. Mine needed 1.3 x the calculated figure, but my water is not RO.

The Bru'n water spreadsheet also does calculations for sparge acidification. Just running that through with the same figures as above, shows no acid is needed. Bru'n water only goes to 1 decimal point though.

EDIT - * I will point out that you will also need to consider your end runnings gravity readings to ensure that you aren't over sparging, which will also increase your chances of extracting some astringent constituents. Rough guide is 1.010 end runnings, though some say higher, some lower. I've had it down to 1.004 without any issues, though I would have stopped earlier if I'd known it was that low.

 

[HaveFun]

Thanks... I will try it next time.

Cheers
Stefan

 

[MHB]

Mostly agree with JOAB, except for the bit about needing to acidify sparge water. I think its vital.
Lacking any other ways to calculate/measure what you are doing to your sparge water, I would treat it the same as my mashing water. Tho measuring is a better option.
There is a move in commercial brewing toward lower mash and kettle pH's, as JOAB calculates it takes very little acid (in this case 88% Lactic) good to know 20 drops is about 1mL (1 drop is 0.05mL), I also suspect there is something not quite right in the 0.01mL addition, worth revisiting the calculation.
Mark